Orthodontic gripping device

ABSTRACT

The present invention relates to an orthodontic gripping device having a body made of a superelastic metal alloy, cold worked titanium beta III, or solution heat treated and aged titanium beta III. The body has first and second, spaced apart arm portions connected to each other. Each arm portion includes a jaw portion having an inner, arch wire-gripping, surface. The inner gripping surfaces are disposed opposite one another in spaced relation with a station defined therebetween for receiving the arch wire. At least a portion of the station is sized smaller than the arch wire. The arm portions are resiliently deflectable outwardly away from each other to admit the arch wire into the station. Once seated in the station, the arch wire is tightly held by inner gripping surfaces so as to resist displacement of the gripping device relative to the arch wire.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/373,968 filed on Dec. 7, 2011, which claims priority under 35 U.S.C.§ 120 to U.S. Provisional Patent Application Ser. No. 61/457,013 filedon Dec. 8, 2010, the disclosure of which is hereby incorporated byreference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the field of orthodontics, inparticular, to an orthodontic gripping device suitable for tightlyclamping onto an arch wire or other orthodontic component.

BACKGROUND OF THE INVENTION

In orthodontics, an arch wire is used in conjunction with orthodonticbrackets mounted to the patient's teeth to move the teeth to desiredpositions. The arch wire is configured to conform generally to thedental arch of the patient and is accommodated or seated within archwire slots defined in the orthodontic brackets. The arch wire exertsforces on the orthodontic brackets which over time cause the teeth tomove to their correct positions.

In orthodontic treatment, it is customary to place arch wire stops atspecific locations on the arch wire to prevent displacement of the archwire in the mesial/distal direction relative to one or more brackets. Insome instances, arch wire stops will be provided to arrest movement atthe free ends of the arch wire to prevent the arch wire from disengagingfrom the arch wire slot of the distalmost bracket and from makingcontact with (and possibly, irritating) the soft tissue (e.g. gums) inthe patient's mouth. In other instances, stops may be used to fix thearch wire to a bracket/tooth combination to effect a particulartransmission of forces to the bracket/tooth combination to achieve aparticular result (e.g. to prevent migration of a tooth along the archwire).

The arch wire stops that have been developed to date use a variety oftechniques and/or structural components to limit mesial/distaldisplacement of the arch wire relative to a bracket. One known designemploys a generally C-shaped clamp provided with an arch wire receivingslot. A closure member is pivotally connected to the clamp and can bemoved between an open position to allow access to the arch wirereceiving slot and a closed position wherein access to the arch wirereceiving is restricted. The closure member has a variable thickness andis formed with an inner camming surface for engagement with the archwire. When the closure member is moved to the open position, the archwire receiving slot remains unobstructed and can receive an arch wire.When the closure member is moved to the closed position, the innercamming surface is brought to bear against the outer surface of the archwire and creates a mechanical constriction (or narrowing) of the archwire slot. As a result, the arch wire is retained between the innerwalls of the clamp and the inner camming surface, and is discouragedfrom moving mesially or distally relative to a bracket by the frictionforces acting on the arch wire.

Still other stops use different movable components to tightly hold thearch wire within the stop. For example, in some stops, a rotatable screwis threadingly engaged with a sleeve so as to project into the arch wireslot defined in the sleeve. As the screw is tightened, its lingual endbears against the outer surface of the arch wire trapping it within thesleeve.

The relatively small size of these types of stops and the fact that theyinclude movable components have tended to make them difficult to handleand deploy in the field. Moreover, there have been some complaints thatonce mounted in the mouth these stops tend to be bulky and may irritatethe patient's cheek or gum tissue as a result of their bulkiness. Thedesign of these stops may also allow food to become trapped within thestop or between the stop and the patient's soft tissue or dentition.Additionally, these stops tend to loosen from, or slip along, the archwire over time.

A more common approach to restricting mesial/distal displacement of anarch wire involves the use of crimpable, tubular or C-shaped, sleeves.The arch wire is inserted through the sleeve and its position is fixedrelative to the arch wire by crimping the sleeve in place. Slippageproblems have been encountered with these types of stops, as the archwire tends to slide within the sleeve when forces are applied to it. Toaddress these concerns, some sleeves have been provided with roughenedor irregular inner wire-engaging surfaces to increase friction andenhance the gripping action of the sleeve. These roughened surfaces maybe obtained by coating the inner wire-engaging surfaces with abrasivematerial or by mechanically roughening the surfaces. These modificationshave tended to lessen the occurrence of slippage of the arch wire.However, handling and slippage problems remain. Threading of the archwire through the sleeve can be challenging as the arch wire itself has arelatively small cross-sectional area and the passageway formed in thesleeve is also quite small. Once threaded on the arch wire (and prior tocrimping) the sleeve can inadvertently move during crimping thus makingprecise positioning difficult.

In light of the foregoing, it would be advantageous to have anorthodontic gripping device or arch wire stop with enhanced grippingaction to overcome the slippage problems heretofore experienced withexisting arch wire stops. Preferably, such an arch wire gripping devicewould be relatively easy to handle and quick to attach on an arch wire.

SUMMARY OF THE INVENTION

According to a broad aspect of an embodiment of the present invention,there is provided an orthodontic gripping device for attaching to anarch wire. The gripping device includes a body made of a materialselected from the group consisting of a superelastic metal alloy, coldworked titanium beta III, and solution heat treated and aged titaniumbeta III. The body has first and second, spaced apart arm portionsconnected to each other. The first arm portion includes a first jawportion having a first inner, arch wire-gripping surface. The second armportion includes a second jaw portion having a second inner, archwire-gripping surface. The first and second inner gripping surfaces aredisposed opposite one another in spaced relation. The space between thefirst and second inner gripping surfaces defines a station for receivingthe arch wire therein. At least a portion of the arch wire receivingstation is sized smaller than the arch wire. The body further includesan entranceway defined between the first and second arm portions. Theentranceway provides access to the arch wire receiving station. Thefirst and second arm portions are resiliently deflectable outwardly awayfrom each other when the arch wire is admitted through the entrancewayinto the arch wire receiving station. The first and second innergripping surfaces engage the arch wire and apply opposing grippingforces against the arch wire so as to resist displacement of thegripping device relative to the arch wire, when the arch wire is seatedwithin the arch wire receiving station.

In another feature, the body is of unitary construction. In a furtheralternative, at least one of the arm portions is a separate component.Optionally, the superelastic metal alloy may be selected from the groupconsisting of: (a) cold worked nickel titanium; (b) cold worked and agednickel titanium; (c) cold worked nickel titanium and other alloyingelements; and (d) cold worked and aged nickel titanium and otheralloying elements. In one feature, the superelastic metal alloy behavesin a linear superelastic mode. In another feature, the superelasticmetal alloy behaves in a non-linear superelastic mode. In alternativefeature, the body is made of a material consisting of: (a) cold workedtitanium beta III; and (b) solution heat treated and aged titanium betaIII.

In an additional feature, the body has a longitudinal centerline. Thefirst and second arm portions are disposed on opposite sides of thelongitudinal centerline and are mirror images of each other.

In yet another feature, the body has a longitudinal centerline and thebody is symmetrical about the longitudinal centerline. Alternatively,the body may be asymmetrical about the longitudinal centerline. In stillanother feature, the body has a transverse centerline and is symmetricalabout the transverse centerline. In a further alternative feature, thebody may be asymmetrical about the transverse centerline.

In one feature, the body further includes a base portion extendingbetween the first and second arm portions to connect one to the other.The entranceway is disposed opposite the base portion.

In another feature, the arch wire has a profile defined by an outersurface. The first and second gripping surfaces are configured tosubstantially conform to at least a portion of the arch wire's outersurface. Additionally, the profile of the arch wire is generallycircular. Each of the first and second inner gripping surfaces has anarcuate profile configured to at least partially match the curvature ofthe arch wire's profile. In a further feature, the arch wire has adiameter. The arch wire receiving station has a substantially circularprofile and a diameter. The diameter of the arch wire receiving stationis sized smaller than the diameter of the arch wire.

In yet another feature, the arch wire has a width. At least a portion ofthe arch wire receiving station is sized smaller than the width of thearch wire. Optionally, the arch wire receiving station may have a widthof constant dimension. The width of the arch wire receiving stationcould be sized smaller than the width of the arch wire. In addition, thebody has a longitudinal centerline. The first and second arm portionsare disposed on opposite sides of the longitudinal centerline. The firstand second arm portions are mirror images of each other. The first andsecond inner gripping surfaces are oriented substantially parallel tothe longitudinal centerline.

In an optional feature, the arch wire has a width. The arch wirereceiving station has a width of variable dimension. The smallest widthof the arch wire receiving station is sized smaller than the width ofthe arch wire. The body has a longitudinal centerline. The first andsecond arm portions are disposed on opposite sides of the longitudinalcenterline and are mirror images of each other. The first and secondinner gripping surfaces have a skewed orientation relative to thelongitudinal centerline. Each gripping surface converges toward theother in the direction of the entranceway.

In an additional feature, each inner gripping surface is a surfaceselected from the group consisting of: (a) a smooth surface; (b) anirregular surface; (c) a textured surface; and (d) a surface coated witha friction enhancing material.

In a further feature, the entranceway is tunnel-shaped and tapers in thedirection of the arch wire receiving station. The entranceway terminatesin a throat and the throat is sized smaller than the size of the archwire. In one optional feature, the throat is sized between 35% and 40%of the diameter of the arch wire. In another optional feature, thethroat is sized between 65% and 70% of the width of the arch wire.

In still another feature, the gripping device further includes anorthodontic accessory formed in the body. The orthodontic accessory isselected from the group consisting of: (a) a hook; (b) an auxiliaryslot; and (c) an eyelet. In another feature, the gripping device furtherincludes a hook extending from the body. Optionally, the hook may beintegrally formed with the body. In another feature, the hook is carriedon the first arm portion. The first arm portion has an outer surface.The hook may extend perpendicular to the outer surface of the first armportion, or alternatively, the hook may extend from the outer surface ofthe first arm portion on a slant.

In yet another feature, the body further includes a base portionextending between the first and second arm portions to connect one tothe other. The hook is carried on the base portion. The base portion hasan outer surface. The hook may extend perpendicular to the outer surfaceof the base portion or alternatively, the hook may extend from the outersurface of the base portion on a slant.

In still another feature, the body further includes an outer surface andthe hook extends from the outer surface of the body.

In a further feature, the arch wire receiving station is shaped toaccommodate an arch wire having a profile selected from the groupconsisting of: (a) a circular profile; (b) a rectangular profile; (c) asquare profile; and (d) a D-shaped profile.

In yet another feature, the gripping device is provided with means forfacilitating handling of the gripping device. The handling means isformed on the body. More specifically, the handling means includes afirst groove defined in the outer surface of the first arm portion and asecond groove defined in the outer surface of the second arm portion.The first groove is disposed opposite the second groove. In anotherfeature, the handling facilitating means includes first and secondlateral wing members extending from the base portion. The first lateralwing member is disposed in spaced relation relative to the first armportion. The second lateral wing member is disposed in spaced relationrelative to the second arm portion. In a further feature, each of thefirst and second lateral wing members has an outer lateral surface andis movable between an undeflected position and a deflected position. Thegripping device has a width measured between the outer lateral surfaceof the first lateral wing member and the outer lateral surface of thesecond lateral wing member. The width of the gripping device when thefirst and second lateral wing members are in the deflected position issmaller than the width of the gripping device when the first and secondlateral wing members are in the undeflected position.

In an additional feature, the arch wire receiving station has a profileselected from the group consisting of: (a) a circular profile; (b) anoval profile; (c) a rectangular profile; (d) a square profile; and (e) aquatrefoil profile.

In one feature, the body has a longitudinal centerline. The arch wirereceiving station has a substantially oval profile defined by a majoraxis and a minor axis. The minor axis is disposed parallel to thelongitudinal centerline. In another feature, the arch wire has adiameter and the arch wire receiving station has a diameter measuredalong the minor axis. The diameter of the arch wire receiving stationmeasured along the minor axis is sized smaller than the diameter of thearch wire.

According to a broad aspect of another embodiment of the presentinvention, there is provided an orthodontic gripping device forattaching to an arch wire. The gripping device includes a body made of ashape memory material having a shape reset temperature range withinwhich the shape memory material is capable of deforming significantlyfrom a memorized shape of the shape memory material and a shape recoverytemperature range within which the shape memory material is capable ofrecovering the memorized shape. The body has first and second, spacedapart arm portions connected to each other. The first arm portionincludes a first jaw portion having a first inner, arch wire-grippingsurface. The second arm portion includes a second jaw portion having asecond inner, arch wire-gripping surface. The first and second innergripping surfaces are disposed opposite one another in spaced relation.The space between the first and second inner gripping surfaces defines astation for receiving the arch wire therein. At least a portion of thearch wire receiving station is sized smaller than the arch wire. Thebody further includes an entranceway defined between the first andsecond arm portions. The entranceway provides access to the arch wirereceiving station. The first and second arm portions are movableoutwardly away from each other when the temperature of the shape memorymaterial of the body lies within the shape reset temperature range andremain spread apart as long as the temperature of the shape memorymaterial lies below the shape recovery temperature range, so as to allowadmission of the arch wire through the entranceway into the arch wirereceiving station. The first and second inner gripping surfaces engagethe arch wire and apply opposing gripping forces against the arch wireso as to resist displacement of the gripping device relative to the archwire, when the arch wire is seated within the arch wire receivingstation and the temperature of the shape memory material of the bodylies within the shape recovery temperature range.

In an additional feature, the shape memory material is selected from thegroup consisting of: (a) a shape memory metal alloy; and (b) a shapememory non-metallic material. In another feature, the shape recoverytemperature range of the shape memory material lies below thetemperature of a patient's oral cavity. In further feature, the shaperecovery temperature range of the shape memory material encompasses thetemperature of a patient's oral cavity. In an alternate feature, theshape recovery temperature range of the shape memory material is abovethe temperature of a patient's oral cavity and the shape resettemperature range of the shape memory material lies below thetemperature of a patient's oral cavity.

According to a broad aspect of another embodiment of the presentinvention, there is provided an orthodontic gripping device forattaching to an arch wire. The gripping device includes a body which hasfirst and second, spaced apart arm portions connected to each other. Thefirst arm portion includes a first jaw portion having a first inner,arch wire-gripping surface. The second arm portion includes a second jawportion having a second inner, arch wire-gripping surface. The first andsecond inner gripping surfaces are disposed opposite one another inspaced relation. The space between the first and second inner grippingsurfaces defines a station for receiving the arch wire therein. At leasta portion of the arch wire receiving station is sized smaller than thearch wire. The body further includes an entranceway defined between thefirst and second arm portions. The entranceway provides access to thearch wire receiving station. The first and second arm portions areresiliently deflectable outwardly away from each other when the archwire is admitted through the entranceway into the arch wire receivingstation. The first and second inner gripping surfaces engage the archwire and apply opposing gripping forces against the arch wire so as toresist displacement of the gripping device relative to the arch wire,when the arch wire is seated within the arch wire receiving station. Ina further feature, the body is made of a resilient spring-back material.

According to a broad aspect of still another embodiment of the presentinvention, there is provided an orthodontic arch wire kit. The kitincludes an arch wire and a gripping device for attaching to an archwire. The gripping device includes a body made of a material selectedfrom the group consisting of a superelastic metal alloy, cold workedtitanium beta III, and solution heat treated and aged titanium beta III.The body has first and second, spaced apart arm portions connected toeach other. The first arm portion includes a first jaw portion having afirst inner, arch wire-gripping surface. The second arm portion includesa second jaw portion having a second inner, arch wire-gripping surface.The first and second inner gripping surfaces are disposed opposite oneanother in spaced relation. The space between the first and second innergripping surfaces defines a station for receiving the arch wire therein.At least a portion of the arch wire receiving station is sized smallerthan the arch wire. The body further includes an entranceway definedbetween the first and second arm portions. The entranceway providesaccess to the arch wire receiving station. The first and second armportions are resiliently deflectable outwardly away from each other whenthe arch wire is admitted through the entranceway into the arch wirereceiving station. The first and second inner gripping surfaces engagethe arch wire and apply opposing gripping forces against the arch wireso as to resist displacement of the gripping device relative to the archwire, when the arch wire is seated within the arch wire receivingstation.

In another feature, the arch wire has a cross-sectional profile selectedfrom the group consisting from: (a) circular; (b) rectangular; (c)square; and (d) D-shaped. In one optional feature, the arch wire isselected from the group consisting of: (a) braided wire strands; (b)helically wrapped strands. Additionally, the arch wire could be selectedfrom the group consisting of: (a) a multi-strand arch wire with a core;and (b) a multi-strand careless arch wire. In another optional feature,the arch wire is a single solid wire.

In still another feature, the arch wire is made of material selectedfrom the group consisting of: (a) a linear elastic material; (b) asuperelastic material; and (c) a shape memory material.

According to a broad aspect of yet another embodiment of the presentinvention, there is provided a dental gripping device for attaching to adental component. The gripping device includes a body made of a materialselected from the group consisting of a superelastic metal alloy, coldworked titanium beta III, and solution heat treated and aged titaniumbeta III. The body has first and second, spaced apart arm portionsconnected to each other. The first arm portion includes a first jawportion having a first inner gripping surface. The second arm portionincludes a second jaw portion having a second inner gripping surface.The first and second inner gripping surfaces are disposed opposite oneanother in spaced relation. The space between the first and second innergripping surfaces defines a station for receiving the dental component.At least a portion of the receiving station is sized smaller than thedental component. The body further includes an entranceway definedbetween the first and second arm portions. The entranceway providesaccess to the receiving station. The first and second arm portions areresiliently deflectable outwardly away from each other when the dentalcomponent is admitted through the entranceway into the receivingstation. The first and second inner gripping surfaces engages the dentalcomponent and applies opposing gripping forces against the dentalcomponent so as to resist displacement of the gripping device relativeto the dental component, when the dental component is seated within thereceiving station.

According to a broad aspect of still another embodiment of the presentinvention, there is provided a gripping device for attaching to anobject to be gripped. The gripping device includes a body made of amaterial selected from the group consisting of a superelastic material,cold worked titanium beta III, and solution heat treated and agedtitanium beta III. The body has first and second, spaced apart armportions connected to each other. The first arm portion includes a firstjaw portion having a first inner gripping surface. The second armportion includes a second jaw portion having a second inner grippingsurface. The first and second inner gripping surfaces are disposedopposite one another in spaced relation. The space between the first andsecond inner gripping surfaces defines a station for receiving theobject to be gripped. At least a portion of the receiving station issized smaller than the object to be gripped. The body further includesan entranceway defined between the first and second arm portions. Theentranceway provides access to the receiving station. The first andsecond arm portions are resiliently deflectable outwardly away from eachother when the object to be gripped is admitted through the entrancewayinto the receiving station. The first and second inner gripping surfacesengages the object to be gripped and applies opposing gripping forcesagainst the object to be gripped so as to resist displacement of thegripping device relative to the object to be gripped, when the object tobe gripped is seated within the receiving station.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the present invention shall be more clearlyunderstood with reference to the following detailed description of theembodiments of the invention taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a perspective view of an orthodontic gripping device inaccordance with a first embodiment of the invention;

FIG. 2A is an end elevation (or mesial) view of the orthodontic grippingdevice shown in FIG. 1;

FIG. 2B is a side elevation view of the orthodontic gripping deviceshown in FIG. 1;

FIG. 3 is another perspective view showing the orthodontic grippingdevice of FIG. 1 attached to an arch wire of circular or substantiallycircular cross-section;

FIG. 4 is an end elevation (or mesial) view of the arch wire andorthodontic gripping device shown in FIG. 3;

FIG. 5A is a perspective view of an orthodontic gripping device inaccordance with a second embodiment of the invention showing anorthodontic gripping device provided with a hook;

FIG. 5B is an end elevation mesial) view of the orthodontic grippingdevice shown in FIG. 5A;

FIG. 5C is a side elevation view of the orthodontic gripping deviceshown in FIG. 5A;

FIG. 6 is a perspective view of an orthodontic pair of pliers inaccordance with an embodiment of the invention used to attach a grippingdevice onto an orthodontic arch wire;

FIG. 7 is a side elevation view of the pliers shown in FIG. 6;

FIG. 8 is an enlarged perspective view of the first male and secondfemale work tips of the pliers illustrated in FIG. 6, showing the pliersin an open setting with the male work tip spaced apart from the femalework tip;

FIG. 9 is an enlarged, isolated perspective view of the female work tipshown in FIG. 8;

FIG. 10 is an end elevation view looking directly at the work tips ofthe pliers illustrated in FIG. 6 with a portion of the work tips removedfor clarity, showing a gripping device of the type shown in FIG. 1seated in a rebate defined in the female work tip of the pliers and theflange of the male work tip bearing against the outer surface of thearch wire;

FIG. 11 is magnified elevation view of the work tips and gripping deviceillustrated in FIG. 10, with the arm portions of the gripping deviceshown deflecting outwardly from each other as the arch wire is admittedthrough the entranceway of the gripping device body;

FIG. 12 is a perspective view of an orthodontic gripping device inaccordance with a third embodiment of the invention;

FIG. 13A is an end elevation (or mesial) view of the orthodonticgripping device shown in FIG. 12;

FIG. 13B is a side elevation view of the orthodontic gripping deviceshown in FIG. 12;

FIG. 14 is another perspective view showing the orthodontic grippingdevice of FIG. 12 attached to an arch wire with a substantiallyrectangular cross-section;

FIG. 15 is an end elevation (or mesial) view of the arch wire andorthodontic gripping device shown in FIG. 14;

FIG. 16 is an end elevation view looking directly at the work tips ofthe pliers illustrated in FIG. 6, showing a gripping device of the typeshown in FIG. 12 seated in a rebate defined in the female work tip ofthe pliers and the flange of the male work tip bearing against the outersurface of the arch wire;

FIG. 17 is magnified elevation view of the work tips and gripping deviceillustrated in FIG. 16 with a portion of the work tips removed forclarity, with the arm portions of the gripping device shown deflectingoutwardly from each other as the arch wire is admitted through theentranceway of the gripping device body;

FIG. 18 is a perspective view of an orthodontic gripping device inaccordance with a fourth embodiment of the invention;

FIG. 19 is an end elevation (or mesial) view of the orthodontic grippingdevice shown in FIG. 18;

FIG. 20 is a perspective view of an orthodontic gripping device inaccordance with a fifth embodiment of the invention; and

FIG. 21 is an end elevation (or mesial) view of the orthodontic grippingdevice shown in FIG. 20;

FIG. 22 is a perspective view of an orthodontic gripping device inaccordance with a sixth embodiment of the invention; and

FIG. 23 is an end elevation (or mesial) view of the orthodontic grippingdevice shown in FIG. 22;

FIG. 24A is a magnified elevation view similar to that illustrated inFIG. 11 showing the female work tip only of the orthodontic pliers andthe gripping device of FIG. 23 with the lateral wing members of thegripping device occupying their respective undeflected positions, priorto insertion of the gripping device into the rectangular rebate of thefemale work tip;

FIG. 24B is a magnified elevation view of the female work tip and thegripping device illustrated in FIG. 24A showing the lateral wing membersof the gripping device moved to their respective deflected positionsthereby allowing the gripping device to fit within the rectangularrebate of the female tip portion;

FIG. 25 is a perspective view of an orthodontic gripping device inaccordance with a seventh embodiment of the invention; and

FIG. 26 is an end elevation (or mesial) view of the orthodontic grippingdevice shown in FIG. 25.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The description, which follows, and the embodiments described thereinare provided by way of illustration of an example, or examples ofparticular embodiments of principles and aspects of the presentinvention. These examples are provided for the purposes of explanationand not of limitation, of those principles of the invention. In thedescription that follows, like parts are marked throughout thespecification and the drawings with the same respective referencenumerals.

As used in this specification, the term “superelastic material” isunderstood to mean a material acting or behaving in a linearsuperelastic mode or in a non-linear superelastic mode. Similarly, a“superelastic metal alloy” means a metal alloy acting or behaving in alinear superelastic mode or in a non-linear superelastic mode. In thecontext of this specification, a material is considered to behave in alinear superelastic mode when it is able to undergo strainsapproximately 4%, without incurring excessive permanent set afterunloading, all the time exhibiting a substantially linear relationshipbetween stress and strain. A material is considered to behave in anon-linear superelastic mode when it exhibits the ability to incurrelatively large amounts of strain without incurring excessive permanentset after unloading, and the loading and unloading stress-strain curvesfor the material are non-linear or multi-linear for the majority oftheir extent.

The term “shape memory material” is understood to mean a material actingor behaving in a shape memory mode. In like fashion, a “shape memorymetal alloy” means a metal alloy acting or behaving in a shape memorymode. In the context of this specification, a material is considered tobehave in a shape memory mode when it has the ability to both undergodeformation of a previously memorized shape and subsequently recoverthat memorized shape when exposed to some type of external stimulus,most commonly a reversible temperature change (as is the case, when thematerial is a metal alloy).

Referring to FIGS. 1, 2A and 2B, there is shown an orthodontic grippingdevice in accordance with a first embodiment of the present inventiondesignated generally with reference numeral 20. The gripping device 20is configured for use with an orthodontic arch wire. The orthodonticgripping device 20 includes a mesial face 22, a distal face 24 and anelongate body 26 extending between the mesial and distal faces 22 and24. In this embodiment, the body 26 is of unitary (one-piece ormonolithic) construction fabricated from a superelastic material.Preferably, such material is a superelastic metal alloy. Mostpreferably, the superelastic metal alloy is nickel titanium, or nickeltitanium and other alloying elements (e.g. chromium (Cr), iron (Fe),vanadium (V), aluminum (Al), copper (Cu), cobalt (Co)), such asnickel/titanium/copper or nickel/titanium/copper/chromium. Preferably,the nickel titanium, or nickel titanium and other alloying elements, iscold worked. Although, cold worked and aged nickel titanium or coldworked and aged nickel titanium and other alloying elements, could alsobe used. In this embodiment, the gripping device 20 is made of coldworked nickel titanium.

However, it should be appreciated that the gripping device could also bemade from other materials suitable for use in orthodontic appliances andexhibiting spring-back properties similar to those exhibited bysuperelastic materials. For example, a gripping device fabricated fromcold worked titanium beta III or solution heat treated and aged titaniumbeta III (a titanium molybdenum alloy) has been found to have superiorgripping strength. Testing has shown that the gripping device could alsobe made of cold worked ELGILOY™ alloy (a cobalt, chromium and nickelalloy). Still other materials may be selected based on their ability toresist permanent deformation and/or mechanical failure when the grippingdevice is flexed during its engagement with the arch-wire, while at thesame time possessing sufficient material stiffness, such that thegripping device exhibits sufficient spring-back to hold the arch-wirefirmly in place once the gripping device is fully engaged with the archwire.

In still other embodiments, the gripping device could be made of a shapememory material, such a shape memory metal alloy. Although, conceivably,a non-metallic material (such as a polymer) possessing shape memoryproperties could also be used.

For reasons of strength and robustness, it is generally preferred thatthe body be made monolithic. However, in certain applications it may hedesirable to have the body fabricated from separate components. Thesecomponents could all be made of the same superelastic or shape memorymaterial. Alternatively, the body could be made of a composite ofsuperelastic materials or a composite of shape memory materials. In afurther alternative embodiment, the body could be made of a composite ofone or superelastic materials with a non-superelastic material or acomposite of one or more shape memory materials with a non-shape memorymaterial.

Preferably, the orthodontic gripping device is manufactured usingmaterial removal techniques. However, it is possible the gripping devicecould also be fabricated using other manufacturing techniques, such asrapid prototyping, sintering, casting, extrusion etc. In cases, wherethe body is made of separate components, each of these components couldbe made using one of the afore-mentioned methods or the like andsubsequently assembled to each other to form the body by laser welding,fusing, or other similar process.

The body 26 has a vaguely rectangular shape or profile when seen in amesial view such as shown in FIG. 2A. The shape of the body 26 isdefined substantially by four smoothly radiused corners—first corner 30,second corner 32, third corner 34 and fourth corner 36. The corners 30,32, 34 and 36 are rounded so as to avoid the formation of abruptprojecting edges which could otherwise irritate the soft tissue in thepatient's mouth and cause discomfort when the orthodontic grippingdevice 20 is deployed in the patient's mouth.

The body 26 includes a longitudinal centreline CL₁ (shown in FIG. 2A), abase portion 38 and a pair of opposed, spaced apart, first and secondarm portions 40 and 42 connected to the base portion 38 and disposed onopposite sides of the longitudinal centerline CL₁. The body 26 issymmetrical about the longitudinal centerline CL₁ such that the armportions 40 and 42 are mirror images of each other. The body 26 is alsoconfigured to be symmetrical about a transverse centerline CL₂ (shown inFIG. 2B). This need not be the case in every application. In otherembodiments, the body could be configured asymmetrically about one orboth the longitudinal centerline CL₁ and the transverse centerline CL₂.

The first arm portion 40 joins the base portion 38 at the first corner30, while the second arm portion 42 attaches to the base portion 38 atthe second corner 32. Each arm portion 40, 42 extends away from corner30, 32, respectively, in a direction generally perpendicular to the baseportion 38. At the third corner 34, the first arm portion 40 turnsinwardly toward the second arm portion 42 and ultimately, terminateswith a first arch wire engaging jaw portion 44. Similarly, the secondarm portion 42 turns inwardly toward the first arm portion 40 at thefourth corner 36 to terminate with a second arch wire engaging jawportion 46.

As shown in FIG. 2A, the first and second jaw portions 44 and 46 arearranged opposite one another and are separated by a relatively smallgap which defines an arch wire receiving slot or station 48 forcaptively engaging (securely retaining) an arch wire 50 therein.Configured in this manner, the first and second jaw portions 44 and 46together define the gripping jaw 52 of the orthodontic gripping device20.

While in the preferred embodiment, the body 26 is formed with twoopposed arm portions 40 and 42 joined to and integrally formed with thebase portion 38, in other embodiments, the body could be configureddifferently. For instance, one or both of the arm portions could befabricated as separate components that are subsequently fixed to thebase portion.

In another embodiment, the body could have two pairs of arms portionsmounted in opposition to each other. In such an embodiment, a first pairof arm portions would include first and second, spaced apart, armportions spaced side-by-side. Similarly, the second pair of arm portionswould include third and fourth, spaced apart, arm portions spacedside-by-side. The first arm portion would be disposed opposite the thirdarm portion, while the second arm portion would be arranged opposite thefourth arm portion. Each of these arm portions would possess an archwire engaging jaw portion. Defined between the jaw portions of the firstand second arm portions, and the jaw portions of the third and fourtharm portions, would be arch wire receiving slots or stations forcaptively engaging (securely retaining) an arch wire therein. Configuredin this manner, the jaw portions of the first and second arm portionstogether would define a first gripping jaw, while the jaw portions ofthe third and fourth arm portions together would define a secondgripping jaw. In still other embodiments, more than two pairs of opposedarm portions may be provided. Moreover, the body could also beconfigured so that two or more, smaller arm portions are mounted inopposition to a single, larger arm portion.

Still other modifications may be brought to the body. In the embodimentshown in FIG. 2A, the body 26 is formed with a well-defined base portion38. In other embodiments, the base portion could be configured to beless prominent a structure. In yet other embodiments, the base portioncould be omitted altogether. In such embodiments, the arm portions wouldconnect to each other.

With reference to FIGS. 2A and 2B, the elongate body 26 further includesa length L₁ measured between the mesial and distal faces 22 and 24 ofthe body 26, a width W₁ measured between the outer lateral surface 60 ofthe first arm portion 40 and the outer lateral surface 62 of the secondarm portion 42, and a depth H₁ measured between the outer surface 64 ofthe base portion 38 and the outer surfaces 66 of the arm portions 40 and42 disposed opposite the outer surface 64. In this embodiment, the body26 is nearly as long as it is wide. In other embodiments, the body maybe configured to have a length L₁ equal to, greater than or lesser thanthe width W₁.

Roughly midway between the third and fourth corners 34 and 36 andopposite the base portion 38, an arch wire entranceway 70 is formedwithin the body 26. The entranceway 70 runs the entire length of thebody 26 and is generally funnel-shaped with a taper in the direction ofthe base portion 38 ultimately culminating in a throat 72. The funnelshape of the entranceway 70 is defined by a pair of opposed, first andsecond inclined body surfaces 74 and 76. The inclined body surfaces 74and 76 are separated from each other by an angle θ₁. In this embodiment,the angle θ₁ measures approximately 60.8 degrees. It will be appreciatedthat in other embodiments, a different (greater or lesser) value for theangle θ₁ may be used. In still other embodiments, the entranceway couldbe configured to have a different shape.

The size of the throat 72 corresponds to the distance T₁ between theinclined body surfaces 74 and 76 at the narrowest point of theentranceway 70. The distance T₁ is selected based on the size/diameterD₁ of the arch wire 50 (or the range of arch wires) to be gripped by theorthodontic gripping device 20. The distance T₁ must be large enough sothat the arch wire 50 can be inserted into the arch wire receivingstation 48 without the application of excessive force. But, care must betaken not to size the throat 72 so large as to permit the arch wire 50to be released easily from the gripping jaw 52 through the throat 72. Ithas been found that sizing the distance T₁ to be within the range ofbetween approximately 35% to approximately 40% of the diameter D₁ tendsto meet the above-described design objectives. In other embodiments, thedistance T₁ can be increased or decreased to suit a differently sizedarch wire or a particular application.

The entranceway 70 (and more specifically, the throat 72) opens onto (orprovides access to) the arch wire receiving station 48. In thisembodiment, opposing, inner gripping surfaces 78 and 80 of the first andsecond jaw portions 44 and 46, respectively, are configured with aconcavity or indentation 82 which impart a generally circular profile tothe arch wire receiving station 48. Configured in this way, the profileof the arch wire receiving station 48 matches at least partially thecross-sectional (i.e. circular or substantially circular) shape of thearch wire 50.

This arrangement tends to maximize contact/engagement between the innergripping surfaces 78 and 80 and the outer surface 84 of the arch wire 50and tends to improve retention of the arch wire 50 within the arch wirereceiving station 48 by ensuring that a proper distribution of grippingforces on the arch wire is achieved. By matching the geometry of thearch wire receiving station 48 to that of the arch wire 50, the risk ofthe arch wire being accidentally released from the gripping device inthe event the arch wire or gripping device is exposed to a suddenimpact, may be mitigated.

While matching the profile of the arch wire receiving station to that ofthe arch wire is generally preferred, it need not be the case in everyapplication. In certain applications, the arch wire receiving stationcould be configured with a profile different from that of the arch wire.

Other modifications are possible. For instance, while in this embodimentthe inner gripping surfaces 78 and 80 maintain the same arcuate profilethroughout the length L₁ of body 26, in other embodiments the profilesof the inner gripping surfaces could be varied throughout the length ofbody. The inner gripping surfaces could feature an irregular surfaceprofile. Instead of the inner gripping surfaces being smooth, they couldbe textured or roughened to enhance friction. Further still, the innergripping surfaces could be coated with friction enhancing materials.

In this embodiment, by virtue of the circular profile of the arch wirereceiving station 48, the centre point for the radius of curvature ofthe inner gripping surface 78 coincides with the centre point for theradius of curvature of the inner gripping surface 80, and both centrepoints lies on the longitudinal centreline CL₁.

The arch wire receiving station 48 has a diameter D₂ definedsubstantially by the opposing inner gripping surfaces 78 and 80. Thediameter D₂ of the arch wire receiving station 48 is sized slightlysmaller than the diameter D₁ of the arch wire 50. Preferably, thediameter D₂ is sized 20% smaller than the diameter D₁. In otherembodiments, the sizing of diameter D₂ may differ.

During the attachment procedure, when the arch wire 50 is received inthe arch wire receiving station 48, the first and second arm portions 40and 42 deflect partially outwardly from each other to compensate for thefact that the diameter D₂ of the arch wire receiving station 48 issmaller than the diameter D₁ of the arch wire 50. Because theorthodontic gripping device 20 is made from a superelastic metal alloy,the arm portions 40 and 42 are resilient and biased to their original(undeflected) positions. As the arm portions 40 and 42 seek to return totheir original positions, their inner gripping surfaces 78 and 80, whichpartially surround the arch wire 50, exert a clamping or gripping forceon the outer surface 84 of the arch wire 50 (as best shown in FIG. 4).The application of this gripping force tends to hold the arch wire 50tightly and tends to resist displacement (or arrest movement) of thegripping device 20 relative to the arch wire 50. It will thus beappreciated that the gripping jaw 52 derives its gripping force byputting to good advantage the special spring-back characteristics of themetal alloy to tightly clamp onto the arch wire 50. As a result, thegripping jaw 52 of the gripping device 20 tends to exert a greatergripping force on the arch wire than conventional arch wire stops andtends to offer better resistance against slippage.

When the gripping device 20 is used as an arch wire stop, movement ofthe arch wire relative to the gripping device will preferably heresisted in the mesial/distal direction. However, it should be notedthat the gripping device would discourage movement in all directions andwould tend to resist rotation about the arch wire.

Opposite the throat 72, the arch wire receiving station 48 opens onto arelatively narrow passageway 88. The passageway 88 extends toward thebase portion 38 and communicates with an arcuate (generally U-shaped)cutout 90 having opposed first and second portion 92 and 94. The firstportion 92 of the cutout 90 is defined between the first arm portion 40and the base portion 38, and follows an arcuate path from the passageway88 toward the third corner 34 of the body 26. The terminal end 96 of thefirst cutout portion 92 lines up roughly with the midpoint of theconcavity 82 defined in the inner gripping surface 78 of the firstgripping jaw portion 44. Configured in this way, the first cutoutportion 92 defines a peninsular section 98 in the first gripping jawportion 44.

In like fashion, the second portion 94 of the cutout 90 is definedbetween the second arm portion 42 and the base portion 38, and followsan arcuate path from the passageway 88 toward the fourth corner 36 ofthe body 26. The terminal end 100 of the second cutout portion 94 linesup roughly with the midpoint of the concavity 82 defined in the innergripping surface 80 of the second gripping jaw portion 46. Configured inthis way, the second cutout portion 94 defines a peninsular section 102in the second gripping jaw portion 46. In other embodiments, cutout 90could be configured differently.

The purpose of the cutout portions 92 and 94 is to permit the deflectionof the gripping jaw portions 44 and 46 outwardly away from each otherwithout the application of excessive force, when the arch wire 50 isbeing pushed through the throat 70 and into the arch wire receivingstation 48. The cutout portions 92 and 94 also allow the peninsularsections 98 and 102 of the gripping jaw portions 44 and 46 to deflecttoward the first and second corners 30 and 32, respectively, when thearch wire 50 is held in the arch wire receiving station 48 (as bestshown in FIG. 4).

Turning now to FIGS. 3 and 4, a length of arch wire 50 is shown firmlyretained by the gripping jaw 52 of the orthodontic gripping device 20.As previously mentioned, the arch wire 50 in this embodiment has acircular or substantially circular cross-section and a diameter D₁. Itmay be fabricated from linear elastic materials (e.g. stainless steel,cobalt chromium, titanium beta (III)), superelastic materials (includingsuperelastic metal alloys, such as alloys of nickel titanium,nickel/titanium/copper, nickel/titanium/copper,nickel/titanium/copper/chromium), shape memory materials (includingshape memory non-metallic materials, such as shape memory polymers; orshape memory metal alloys), or still other materials possessingsuperelastic or shape memory properties and suitable for use inorthodontic appliances.

For ease of illustration, the arch wire 50 is shown conceptually asbeing a single solid strand of wire. However, the arch wire 50 can takethe form of a plurality of braided wire strands or helically wrappedwire strands. An example of such a helically wrapped arch wire is thearch wire manufactured and sold by Strite Industries Limited ofCambridge, Ontario, Canada under the brand name SPEED Supercable™. Thearch wire used in conjunction with the gripping device 20 can have acore or alternatively, it may be coreless (i.e. it may have a hollowcylindrical centre). An example of such a coreless arch wire is an archwire manufactured and sold by Strite Industries Limited under the brandname SPEED Tubular Supercable™. In a further alternative, the arch wirecan take the form of a Hills Dual Geometry Wire, that is, a wire with afirst section provided with a square cross-section and second sectionprovided with a circular cross-section. In such a case, the orthodonticgripping device 20 could be used on the second section of circularcross-section.

Referring to FIGS. 6, 7, 8 and 9, there is shown an orthodontic tool inthe nature of a pair of pliers 110 which may be used to attach thegripping device 20 to the arch wire 50. The pliers 110 have first andsecond arms 112 and 114 arranged in cross-wise fashion and pivotallyconnected to each other by a pivot connector 116. The first arm 112includes a first end 118, an opposed second end 120, a first curvedhandle portion 122, a first beak portion 124 and a first transitionportion 126 for joining the first handle portion 122 to the first beakportion 124. The first transition portion 126 is disposed at a locationcloser to the first end 118 than to the second end 120 and receives aportion of the pivot connector 116. The first handle portion 122 extendsfrom the second end 120 to the first transition portion 126, while thefirst beak portion 124 runs from the first transition portion 126 to thefirst end 118. The first beak portion 124 has a generally taperingprofile, but terminates with a first work tip 128 that extends on aslant relative to the longitudinal axis P of the pliers 110. In thisembodiment, the angle α formed between the longitudinal axis P and thework tip 128 is 30 degrees (see FIG. 7). In other embodiments, adifferent angle α may be used.

The second arm 114 is generally structurally similar to the first arm112 in that it too has a first end 130, an opposed second end 132, asecond curved handle portion 134, a second beak portion 136 and a secondtransition portion 138 joining the second handle portion 134 to thesecond beak portion 136. The second transition portion 138 is disposedat a location closer to the first end 130 than to the second end 132 andreceives another portion of the pivot connector 116. Configured in thismanner, the arms 112 and 114 are joined to each other by the pivotconnector 116 at their respective transition portions 126 and 138. Thesecond handle portion 134 extends from the second end 132 to the secondtransition portion 138, while the second beak portion 136 runs from thesecond transition portion 138 to the first end 130. The second beakportion 136 also has a generally tapering profile (as best shown in FIG.6), but terminates with a second work tip 140 that extends on the sameslant relative to the longitudinal axis P of the pliers 120 as work tip128.

With reference to FIGS. 8 and 9, the first and second work tips 128 and140 are now described in greater detail. The first work tip 128 has agenerally block-like body 142 with an inner surface 144 oriented towardthe second work tip 140. Projecting from the inner surface 144 in agenerally perpendicular orientation is a flange 146. The flange 146extends along the entire width of the body 142 and is carried close tothe free end 148 of the work tip 128. As will be explained in greaterdetail below, the flange 146 is configured for registration with atransverse slot 150 defined within the second work tip 140. In analternative embodiment, the flange could be configured differently.

Referring now specifically to FIG. 9, the second work tip 140 alsoincludes a generally block-like body 152 with an inner surface 154oriented toward the first work tip 128. The inner surface 154 is formedwith the first, generally C-shaped, transverse slot 150 which spans thewidth of the body 152. The first transverse slot 150 is sized toaccommodate a section of arch wire therein. In an alternativeembodiment, the first transverse slot could be configured differently,for instance, it could be stepped so as to suit different sized archwires.

A rectangular pocket or rebate 158 defined within the inner surface 154partially overlies the transverse slot 150 with its short sides orientedgenerally parallel to the transverse slot 150. Advantageously, therectangular rebate 158 is configured as a seat for holding anorthodontic gripping device, such as the gripping device 20, duringattachment of the gripping device to the arch wire. The provision ofthis seat tends to minimize the incidents of accidental drop or loss ofthe gripping devices 20 and facilitates handling of the grippingdevices, which because of their relatively small size can be unwieldy.In other embodiments, the handling of the gripping devices could beimproved by incorporating a spring-loaded mechanism into the rectangularrebate to securely retain the gripping device. Alternatively, one of thesecond work tip and the gripping device could be coated with a tackymaterial which would assist in holding the gripping device on the pliers110.

The body 152 is further provided with a second transverse slot 160recessed from both the first transverse slot 150 and the rebate 158. Thesecond transverse slot 160 is co-extensive with, and generally parallelto, the short sides of the rebate 158. The second transverse slot 160provides a clearance to accommodate any protrusions extending from thebase portion 38 which may be left over from the gripping devicemanufacturing process. Additional slots may be provided for the samepurpose.

The arms 112 and 114 of the pliers 110 are movable relative to eachother between a closed setting (not shown) and an open setting 162 (bestshown in FIG. 8). In the closed setting, the flange 146 of the firstmale work tip 128 mates with the slot 150 of the second female work tip140. In the open setting 162, a gap exists between the first and secondwork tips 128 and 140. To move the arms 112 and 114 from the opensetting 162 to the closed setting, the user brings the first and secondhandle portions 122 and 134 toward each other. The arms 112 and 114 aremade to pivot about the pivot connector 116 causing the first and secondbeak portions 124 and 136 to move toward each other thereby closing thegap between the first and second work tips 128 and 140. In analternative embodiment, the pliers may be spring-loaded.

In a further embodiment, the arrangement of flange 146, first and secondtransverse slots 150 and 160 and rectangular rebate 158 could beoriented differently on the first and second work tips 128 and 140. Forinstance, in another embodiment, the arrangement could be rotated 90degrees from the arrangement shown in FIG. 8.

An exemplary procedure for attaching the orthodontic gripping device 20to the arch wire 50 using the orthodontic pliers 110 is now explained ingreater detail. The orthodontist moves the arms 112 and 114 of thepliers 110 to the open setting 162 and orients the pliers such that thesecond arm 114 is disposed above the first arm 112. In this position,the rectangular rebate 158 defined in the second work tip 140 isaccessible from the top. The orthodontist then places an orthodonticgripping device 20 into the second work tip 140 ensuring that thegripping device 20 is properly seated in the rectangular rebate 158 withits entranceway 70 oriented co-axially with the first transverse slot150 and facing toward the first work tip 128. The proper placement ofthe gripping device 20 within the rebate 158 is facilitated by thegenerally rectangular shape of the gripping device body 26 as the body26 tends not to rotate in the rebate 158. The gripping device 20 is nowready to be attached to the arch wire 50.

The orthodontist can attach the gripping device 20 on the arch wire 50either while the arch wire 50 is fitted on the patient's dental arch orprior to the placement the arch wire 50 in the orthodontic appliances orbrackets mounted to the patient's teeth. The orthodontist positions thepliers 110 over the section of arch wire to be retained within thegripping device 20 and aligns that section of arch wire 50 with theentranceway 70 (defined in the gripping device body 26) and the firsttransverse slot 150 of the second work tip 140. Preferably, if thegripping device 20 is being attached to an arch wire 50 already fittedon the patient's upper dental arch, the entranceway 70 would be directedtoward the gingival. On the other hand, if the gripping device 20 isbeing attached to an arch wire 50 already fitted on the patient's lowerdental arch, preferably, the entranceway 70 would be directed toward theocclusal. This further helps to avoid the gripping device 20accidentally falling out of the pliers 110 during the attachmentprocedure. This need not be the case in every application. In otherembodiments, it may be possible to orient the entranceway 70differently, for example, toward the lingual or toward the labial.

The orthodontist then squeezes the handle portions 122 and 134 togetherthereby causing the flange portion 146 of the first work tip 128 to actupon the section of arch wire 50 to be retained (as best shown in FIG.10). The flange portion 146 holds the arch wire 50 in place while thesecond work tip 140 causes the inclined body surfaces 74 and 76 to pressagainst the arch wire. With the application of sufficient force, the anportions 40 and 42 of the gripping device 20 will begin to deflectoutwardly from each other and the throat 72 will widen to accommodatethe arch wire 50 therein (see FIG. 11). Once the arch wire 50 hascleared the throat 72, the arm portions 40 and 42 will flex back towardeach other in an attempt to return to their original (undeflected)positions. The inner gripping surfaces 78 and 80 of the first and secondjaw portions 44 and 46 will come to bear on the outer surface 84 of thearch wire 50 and will hold the arch wire 50 tightly within the grippingdevice 20 thereby discouraging displacement of the gripping device 20relative to the arch wire 50. With the gripping device 20 now attachedto the arch wire 50, the orthodontist can move the arms 112 and 114 ofthe pliers 110 to the open setting 162 and release the gripping device20 from the tool.

It should be appreciated that the orthodontic pliers 110 arespecifically designed for the gripping device 20 and other similargripping devices. Accordingly, while it is generally preferred for easeand convenience that the pliers 110 be used to attach a gripping device20 or other similar gripping device to an arch wire, this need not bethe case in every application. Other tools could be employed to attachthe gripping device 20 or other like gripping device to the arch wire.

In the embodiment shown and described, the gripping device 20 is made ofnickel titanium, a metal alloy that behaves in a linear superelasticmode. It should be appreciated that the exemplary attachment proceduredescribed above applies specifically to gripping devices made of metalalloys behaving in a superelastic mode. Where the gripping device is amaterial that behaves in a shape memory mode, the attachment procedurewould differ as explained below.

As an initial step, the gripping device would be cooled to a temperaturewithin a temperature range that allows significant deformation of thememorized shape of the shape memory material (referred to herein as theshape reset temperature range). Cooling may be achieved by placing thegripping device in contact with cooling device or cooling media such asdry ice, right up to the time in time when it is to be deployed. Asimilarly cooled tool would be then inserted into the entranceway of thegripping device body to cause the arms of the gripping device to deflectoutward. Because the temperature of the gripping device is below theshape recovery temperature range of shape memory material (i.e. thetemperature range within which the shape memory material recovers itsmemorized shape), the arms would remain in their respective flexed ordeflected positions even after removal of the tool, and the entrancewaywould remain open large enough to allow an arch wire of the desireddiameter or width to pass through it and into the jaw of the grippingdevice.

Thereafter the orthodontist would rapidly place the gripping device inthe desired position over an arch wire installed in a patient's oralcavity or exterior to the patient's oral cavity (in both cases such thatthe arch wire is located within the jaws of the gripping device). Thegripping device would then be heated up to a temperature falling withinthe shape recovery temperature range. As the gripping device reaches atemperature within the shape recovery temperature range, the shapememory properties in the material cause the arms to move back towardeach other in an attempt to return to their original (undeflected)positions. The inner gripping surfaces of the first and second jawportions come to bear on the outer surface of the arch wire and hold thearch wire tightly within the gripping device thereby discouragingdisplacement of the gripping device relative the arch wire.

In certain embodiments, it may be desirable to have a shape recoverytemperature range that is below the temperature of the human oral cavity(which is on average 36.8° C. but may vary among individuals and time ofday). For example, where the shape memory material is nickel titanium, ashape recovery temperature range of between −15° C. and 5° C. could beemployed. Of course, other temperature ranges could also be used. Inthis way, shape memory of the gripping device may be obtained simply byallowing the gripping device to warm back up to the natural temperaturein the oral cavity. During this time, it is recommended that thegripping device be held in position at the desired point of attachmenton the arch wire to avoid sliding or shifting of the gripping devicealong the arch wire. Given the relatively small size of the grippingdevice, this should take a very short time. In alternative embodiments,the shape recovery temperature range could encompass the temperature ofa patient's oral cavity. In such embodiments, the shape recoverytemperature range could be, for example, between 17° C. and 37° C.

In still other embodiments, the shape recovery temperature range couldbe higher than the temperature of the human oral cavity (but less thanthe temperature at which permanent plastic deformation occurs), forexample, between 45° C. and 60° C. In such cases, a shape memorymaterial having a shape reset temperature range that is below thetemperature of the human oral cavity should be used, for example,between 36° C. and 0° C. Such a shape memory material should have ashape recovery temperature range sufficiently high such that thegripping device does not require constant cooling subsequent to beingopened at low temperature. Moreover, the shape memory material would beselected to ensure that the gripping device retains sufficient grippingforce when it cools to the temperature of the human oral cavity.

When the shape recovery temperature range is set higher than thetemperature of the human oral cavity, the gripping device can be shippedand handled at ambient temperature and somewhat higher temperatures,including that of the human oral cavity, without causing the jaw of thegripping device to close. In such cases when attaching the grippingdevice to the arch wire, care should be taken to localize theapplication of the heat applied to the gripping device during theinstallation on an arch wire, and to take measures to prevent anythermal damage to the teeth or surrounding tissue near the point ofinstallation.

Referring to FIGS. 5A, 5B and 5C, there is shown a second embodiment ofan orthodontic gripping device constructed in accordance with theprinciples of the present invention. The gripping device in thisembodiment is designated generally with reference numeral 170 and issimilar in all material respects (i.e. functionality, configuration andconstruction) to the gripping device 20 shown in FIGS. 1 to 3, exceptthat gripping device 170 is provided with a hook 172 which depends fromthe gripping device body 174.

The body 174 is similar to the body 26 in that it too includes alongitudinal centerline CL₁ (shown in FIG. 5B), a transverse centerlineCL₂ (shown in FIG. 5C), a base portion 176 and a pair of opposed, spacedapart, first and second arm portions 178 and 180 connected to the baseportion 176 and disposed on opposite sides of the centerline CL₁. Thebody 174 is symmetrical about the longitudinal centerline CL₁ such thatthe arm portions 178 and 180 are mirror images of each other. The bodyis also configured to be symmetrical about the transverse centerlineCL₂.

However, in contrast to body 26, the body 174 has the hook 172 connectedto the outer surface 182 of the base portion 176 and extending away fromthe first and second arm portions 178 and 180 along the centreline CL₁.In this embodiment, the hook 172 is integrally formed with the body 174.This need not be the case in every application. In other embodiments,the hook could be fabricated as a separate component and releasably orpermanently fixed to the gripping device body.

Other modifications are also possible. For instance, the hook need notextend perpendicular to the base portion. It could extend from the baseportion on a slant. While in this embodiment, the hook is centrallydisposed on the base portion in alignment with the entranceway, inalternative embodiments, the hook could be positioned differently inrelation to one of, or both, the base portion and the entranceway. Instill other embodiments, the hook could be carried on one of the armportions instead of on the base portion. The hook could extend from thearm portion in a perpendicular or slanted orientation. In embodimentswhere the hook is carried on one of the arm portions, it may bedesirable to make the arm portion carrying the hook more robust (i.e.bigger and/or thicker) to better resist the forces applied to it by thehook. Conceivably, the hook could be mounted on any exterior surface ofthe gripping device body.

The hook 172 has a proximal end 184, a free end 186 and a stem 188 whichextends between the proximal and free ends 184 and 186. At the proximalend 184, the stem 188 flares outwardly on all sides with smoothlyradiused surfaces. At a location closer to the free end 186 than to theproximal end 184, the stem 188 again flares outwardly in all sides withsmoothly radiused surfaces only to taper inwardly again a short distancelater. This configuration defines the bulbous tip 190 of the hook 172.In other embodiments, the hook 172 could be shaped differently.

In the embodiment shown in FIGS. 5A, 5B and 5C, the gripping device 170is shown provided with a hook 172. In other embodiments, the grippingdevice could be outfitted with accessories other than a hook. Forinstance, in an alternative embodiment, an auxiliary slot or an eyeletcould be formed in the body of the gripping device.

During orthodontic treatment, the gripping device 170 may serve a dualpurpose—it can arrest movement of the arch wire in the mesial/distaldirection while serving as an anchoring point for tying orthodonticelastic/elastomeric bands or ligature ties (metal or elastomeric) ortraction force springs.

The gripping device 170 may be attached to the arch wire 50 in much thesame manner as the gripping device 20. However, the pliers 110 wouldhave to be modified to provide a larger clearance than that currentlyprovided by second transverse rebate 160 in order to accommodate thehook 172.

In the embodiments shown in FIGS. 1 through 5C, the gripping devices 20and 170 are configured to receive and clamp tightly onto an arch wire ofcircular cross-section. However, this need not be the case in everyapplication. In a third embodiment illustrated in FIGS. 12 to 17, thereis shown an orthodontic gripping device 200 which is configured for usewith an arch wire 202 of substantially rectangular cross-section.

Referring to FIGS. 12, 13A and 13B, the gripping device 200 is generallysimilar to gripping device 20 described above in that it too has amesial face 204 and a distal face 206 and an elongate body 208 extendingbetween the mesial and distal faces 204 and 206. In this embodiment, thebody 208 is of unitary (one-piece or monolithic) construction fabricatedfrom a superelastic material. Preferably, such material is asuperelastic metal alloy. Most preferably, the superelastic metal alloyis nickel titanium, or nickel titanium and other alloying elements (e.g.chromium (Cr), iron (Fe), vanadium (V), aluminum (Al), copper (Cu),cobalt (Co)), such as nickel/titanium/copper ornickel/titanium/copper/chromium. Preferably, the nickel titanium, ornickel titanium and other alloying elements, is cold worked. Although,cold worked and aged nickel titanium, or cold worked and aged nickeltitanium and other alloying elements, could also be used. In thisembodiment, the gripping device 200 is made of cold worked nickeltitanium.

However, it should be appreciated that the gripping device could also bemade from other materials suitable for use in orthodontic appliances andexhibiting spring-back properties similar to those exhibited bysuperelastic materials. For example, a gripping device fabricated fromcold worked titanium beta III or solution heat treated and aged titaniumbeta III (a titanium molybdenum alloy) has been found to have superiorgripping strength. Still other materials may be selected based on theirability to resist permanent deformation and/or mechanical failure whenthe gripping device is flexed during its engagement with the arch-wire,while at the same time possessing sufficient material stiffness, suchthat the gripping device exhibits sufficient spring-back to hold thearch-wire firmly in place once the gripping device is fully engaged withthe arch wire.

In still other embodiments, the gripping device could be made of a shapememory material, such a shape memory metal alloy. Although, conceivably,a non-metallic material (such as a polymer) possessing shape memoryproperties could also be used.

Like body 26 of gripping device 20, the body 208 has a vaguelyrectangular shape or profile when seen in a mesial view such as shown inFIG. 13A. The shape of the body 208 is defined substantially by foursmoothly radiused corners—first corner 210, second corner 212, thirdcorner 214 and fourth corner 216. The corners 210, 212, 214 and 216 arerounded so as to avoid the formation of abrupt projecting edges whichcould otherwise irritate the soft tissue in the patient's mouth andcause discomfort when the orthodontic gripping device 200 is deployed inthe patient's mouth.

The body 208 includes a longitudinal centreline CL₁ (shown in FIG. 13A),a transverse centerline CL₂ (shown in FIG. 13B), a base portion 218 anda pair of opposed, spaced apart, first and second arm portions 220 and222 connected to the base portion 218 and disposed on opposite sides ofthe longitudinal centerline CL₁. The body 208 is symmetrical about thelongitudinal centerline CL₁ such that the arm portions 220 and 222 aremirror images of each other. The body 208 is also configured to besymmetrical about a transverse centerline CL₂. In other embodiments, thebody could be configured asymmetrically about one or both thelongitudinal centerline CL₁ and the transverse centerline CL₂.

The first arm portion 220 joins the base portion 218 at the first corner210, while the second arm portion 222 attaches to the base portion 218at the second corner 212. Each arm portion 220, 222 extends away fromcorner 210, 212, respectively, in a direction generally perpendicular tothe base portion 218. At the third corner 214, the first arm portion 220turns inwardly toward the second arm portion 222 and ultimately,terminates with a first stub-like projection 224. The section of thefirst arm portion 220 which runs between the first stub-like projection224 and the base portion 218 defines a first jaw portion 226. Similarly,the second arm portion 222 turns inwardly toward the first arm portion220 at the fourth corner 216 to terminate with a second stub likeprojection 228. The section of the second arm portion 222 which runsbetween the second stub-like projection 228 and the base portion 218defines a second jaw portion 230.

The first and second jaw portions 226 and 230 are arranged opposite oneanother and separated by a relatively small gap which defines an archwire receiving slot or station 232 for captively engaging (securelyretaining) the arch wire 202 therein. Configured in this manner, thefirst and second jaw portions 226 and 230 together define the grippingjaw 234 of the orthodontic gripping device 200 (as best shown in FIG.12).

With reference to FIGS. 12, 13A and 13B, the elongate body 208 furtherincludes a length L₂ measured between the mesial and distal faces 204and 206, a width W₂ measured between the outer lateral surface 240 ofthe first arm portion 220 and the outer lateral surface 246 of thesecond arm portion 222, and a depth H₂ measured between the outersurface 248 of the base portion 218 and the outer surfaces 250 of thearm portions 220 and 222 disposed opposite to the outer surface 248. Inthis embodiment, the body 208 is nearly as long as it is wide. In otherembodiments, the body may be configured to have a length L₂ equal to,lesser than or greater than the width W₂.

Roughly midway between the third and fourth corners 214 and 216 andopposite the base portion 218, an arch wire entranceway 252 is formedwithin the body 208. The entranceway 252 runs the entire length of theelongate body 208 and is generally funnel-shaped with a taper in thedirection of the base portion 218 ultimately culminating in a throat254. The funnel shape of the entranceway 252 is defined by a firstinclined surface 256 presented by the first stub-like projection 224 anda second inclined surface 258 presented by the second stub-likeprojection 228. The inclined body surfaces 256 and 258 are separatedfrom each other by an angle θ₂ (not represented in the figures). In thisembodiment, the angle θ₂ measures approximately 24 degrees. It will beappreciated that in other embodiments, a different (greater or lesser)value for the angle θ₂ may be used.

The size of the throat 254 corresponds to the distance T₂ between theinclined surfaces 256 and 258 at the narrowest point of the entranceway252. The distance T₂ is selected based on the size (i.e. width W₃) ofthe arch wire 202 (or the range of arch wires) to be retained by theorthodontic gripping device 200. The distance T₂ must be large enough sothat the gripping device 200 can be fitted onto the arch wire 202without the application of excessive force. But, care must be taken notto size the throat 254 so large as to permit the arch wire 202 to bereleased easily from the gripping jaw 234 through the throat 254. It hasbeen found that sizing the distance T₂ to be within the range of betweenapproximately 65% to approximately 70% of the width W₃ tends to meet theabove-described design objectives. In other embodiments, the distance T₂can be increased or decreased to suit a differently sized arch wire or aparticular application.

The entranceway 252 (and more specifically,the throat 254) opens onto(or provides access to) the arch wire receiving station 232. In thisembodiment, the arch wire receiving station 232 is shaped generally likea quatrefoil (but for the missing fourth side corresponding to thelocation of the throat 254). Defining this quatrefoil-like shape arefour rounded undercuts or clearances formed in the body 208—a firstundercut 260 located adjacent the first corner 210, a second undercut262 located adjacent the second corner 212, a third undercut 264 locatedadjacent the third corner 214 and a fourth undercut 266 located adjacentthe fourth corner 216—and three inner surfaces—a pair of opposing, innergripping surfaces 268 and 270 of the first and second jaw portions 226and 230 and an inner surface 272 of the base portion 218 as best shownin FIG. 13A. The undercuts 260, 262, 264 and 266 are provided toaccommodate the radiused corners 274, 276, 278 and 280 of the arch wire202. While not generally preferred, in alternative embodiments, the archwire receiving station could be configured without any undercuts. Forexample, the arch wire receiving station could have a generally squareor rectangular profile.

The inner surface 272 defines a seat for supporting side 288 of the archwire 202. It extends between the first and second undercuts 260 and 262and is substantially parallel with the outer surface 248 of the baseportion 218.

The inner gripping surface 268 of the first jaw portion 226 extendsbetween the first and third undercuts 260 and 264, while the innergripping surface 270 of the second jaw portion 230 runs between thesecond and fourth undercuts 262 and 266. Each of the inner grippingsurfaces 268 and 270 has a slightly skewed orientation relative to thelongitudinal centerline CL₁. More specifically, as the inner grippingsurface 268 extends from the first undercut 260 to the third undercut264 it tapers inwardly toward the opposed gripping surface 270.Similarly, the inner gripping surface 270 tapers inwardly toward thegripping surface 268 in the direction of the fourth undercut 266. Stateddifferently, the first and second inner gripping surfaces 268 and 270can be said to converge toward each other in the direction of theentranceway 252. In this embodiment, the angle of taper θ₃ for eachgripping surface 268, 270 (as measured between a vertical axis V(generally parallel to the longitudinal centerline CL₁) and each innergripping surface 268, 270, as the case may be) is 3 degrees.

This taper tends to encourage better contact/engagement between thegripping surfaces 268 and 270 and the lateral sides 284 and 286 of thearch wire 202 when the arch wire 202 is received within the arch wirereceiving station 232 and the arm portions 220 and 222 are partiallydeflected. This tends to improve retention of the arch wire 202 withinthe arch wire receiving station 232 by ensuring that a properdistribution of gripping forces on the arch wire is achieved. In thisway, the risk of the arch wire being accidentally released from thegripping device in the event the arch wire or gripping device is exposedto a sudden impact, may be mitigated.

In other embodiments, a different (i.e. greater or lesser angle of taperθ₃ for both inner gripping surfaces may be used. In a furtheralternative, these inner gripping surfaces could be provided with notaper whatsoever. In such an embodiment, the first and second innergripping surfaces would be oriented substantially parallel to thelongitudinal centerline CL₁.

Preferably, the width of the arch wire receiving station 232 at itsnarrowest point (as measured between the inner gripping surfaces 268 and270 at the location where these surfaces meet with the third undercut264 and the fourth undercut 266, respectively) is at least 10% smallerthan the width W₃ of the arch wire 202. However, in other embodiments,the width of the arch wire receiving station could be sized differently.

Other modifications are possible. For instance, while in this embodimentthe inner gripping surfaces 268 and 270 maintain the same profilethroughout the length L₂ of body 208, in other embodiments the profilesof the inner gripping surfaces could be varied throughout the length ofbody. The inner gripping surfaces could be irregular. Instead of theinner gripping surfaces being smooth, they could be textured orroughened to enhance friction. Further still, the inner grippingsurfaces could be coated with friction enhancing materials.

In this embodiment, because the inner gripping surfaces 268 and 270 havea skewed orientation, the gap or distance G between the surfaces 268 and270 is not constant. The gap G at the narrowest point between the innergripping surfaces 268 and 270 (i.e. where the gripping surfaces 268meets the third undercut 264 and the gripping surface 270 meets thefourth undercut 266) is sized smaller than the width W₃. In embodimentswhere the inner gripping surfaces are oriented substantially parallel tothe longitudinal centerline CL₁, the gap G as measured at any locationbetween the inner gripping surfaces will also be sized smaller that thewidth W₃.

During the attachment procedure, when the arch wire 202 is received inthe arch wire receiving station 232, the first and second arm portions220 and 222 deflect partially outwardly from each other to compensatefor the fact that the gap G measured at the narrowest point between theinner gripping surfaces 268 and 270 is smaller than the width W₃ of thearch wire 202. Because the orthodontic gripping device 200 is made froma superelastic metal alloy, the arm portions 220 and 222 are resilientand biased to their original (undeflected) positions. As the armportions 220 and 222 seek to return to their original positions, theirinner gripping surfaces 268 and 270 apply a clamping or gripping forceon the lateral sides 284 and 286 of the arch wire 202 (as best shown inFIG. 15). The application of this gripping force tends to hold the archwire 202 tightly and tends to resist displacement (or arrest movement)of the gripping device 200 relative to the arch wire 202. It will thusbe appreciated that the gripping jaw 234 derives its gripping force byputting to good advantage the special spring-back characteristics of themetal alloy to clamp tightly onto the arch wire 202. As a result, thegripping jaw 234 of the gripping device 200 tends to exert a greatergripping force on the arch wire than conventional arch wire stops andtends to offer better resistance against slippage.

When the gripping device 200 is used as an arch wire stop, displacementwill preferably be resisted in the mesial/distal direction. However, itshould be noted that the gripping device would also discourage movementin all directions and also tends to resist rotation about the arch wire.

Turning now to FIGS. 14 and 15, a length of arch wire 202 is shownfirmly retained by the gripping jaw 234 of the orthodontic grippingdevice 200. The arch wire 202 in this embodiment has a rectangular orsubstantially rectangular cross-section defined by lateral sides 284 and286 (i.e. the short sides) extending between rounded corners 274 and278, and rounded corners 276 and 280, respectively, and opposed sides282 and 288 (i.e. the long sides) running between rounded corners 278and 280, and rounded corners 274 and 276. The width W₃ of the arch wire202 is defined as the distance between the lateral sides 284 and 286,while the depth H₃ of the arch wire 202 is defined by the distancebetween the sides 282 and 288.

For ease of illustration, the arch wire 202 is shown conceptually asbeing a single solid strand of wire. However, the arch wire 202 can takethe form of a plurality of braided wire strands or helically wrappedwire strands. This multi-stranded arch wire may be formed (e.g. byrolling) to have a generally rectangular cross-section with roundedcorners and may possess a core or be careless.

Attachment of the orthodontic gripping device 200 to the arch wire 202is similar to the attachment of the gripping device 20 to arch wire 50described above. The orthodontist moves the arms 112 and 114 of thepliers 110 to the open setting 162 and orients the pliers such thatsecond arm 114 is disposed above the first arm 112. In this position,the rectangular rebate 158 defined in the second work tip 140 isaccessible from the top. The orthodontist then places an orthodonticgripping device 200 into the second work tip 140 ensuring that thegripping device 200 is properly seated in the rectangular rebate 158with its entranceway 252 oriented parallel to the first transverse slot150. The gripping device 200 is now ready to be attached to the archwire 202.

The orthodontist can attach the gripping device 200 on the arch wire 202either while the arch wire 202 is fitted on the patient's dental arch orprior to the placement of the arch wire 202 in the orthodonticappliances or brackets mounted to the patient's teeth. The orthodontistpositions the pliers 110 over the section of arch wire to be retainedwithin the gripping device 200 and aligns that section of arch wire withthe entranceway 252 (defined in the gripping device body 208) and thefirst transverse slot 150 of the second work tip 140. Preferably, if thegripping device 200 is being attached to an arch wire 202 already fittedon the patient's upper dental arch, the entranceway 252 will be directedtoward the gingival. On the other hand, if the gripping device 200 isbeing attached to an arch wire 202 already fitted on the patient's lowerdental arch, preferably, the entranceway 252 will be directed toward theocclusal. This further helps prevent the gripping device 200 fromaccidentally falling out of the pliers 110 during the attachmentprocedure. This need not be the case in every application. In otherembodiments, it may be possible to orient the entranceway 252differently, for example, toward the lingual or toward the labial.

The orthodontist then squeezes the handle portions 122 and 134 togetherthereby causing the flange portion 146 of the first work tip 128 to actupon the section of arch wire 202 to be retained (as best shown in FIG.16). The flange portion 146 holds the arch wire 202 in place while thesecond work tip 140 causes the inclined body surfaces 256 and 258 topress against the arch wire. With the application of sufficient force,the arm portions 220 and 222 of the gripping device 200 will begin todeflect outwardly from each other and the throat 254 will widen toaccommodate the arch wire 202 therein (see FIG. 17). Once the arch wire202 has cleared the throat 254, the arm portions 220 and 222 will flexback toward each other in an attempt to return to their original(undeflected) positions. The inner gripping surfaces 268 and 270 of thefirst and second jaw portions 226 and 230 will come to bear on thelateral faces 284 and 286 of the arch wire 202 and will hold the archwire 202 tightly within the gripping device 200 thereby discouragingdisplacement of the arch wire 200 in any direction. With the grippingdevice 200 now attached to the arch wire 202, the orthodontist can movethe arms 112 and 114 of the pliers 110 to the open setting 162 andrelease the gripping device 200 from the tool.

In the embodiment shown and described, the gripping device 200 is madeof nickel titanium, a metal alloy that behaves in a linear superelasticmode. Where the gripping device is a material that behaves in a shapememory mode, the attachment procedure would be similar to that describedabove at paragraphs [00109] to [00113].

It will be appreciated that the gripping device 200 could be used withan arch wire having a rectangular cross-section defined by right anglecorners. With appropriate modifications the gripping device 200 couldalso be used with an arch wire of square cross-section (defined by rightangle corners or rounded corners). Further still, the principles of thepresent invention could be applied to design a gripping device suitablefor use with arch wires having cross-sections other than circular,rectangular or square. For instance, a gripping device could beconfigured to clamp onto an arch wire having a generally D-shapedprofile (such as, the SPEED D-Wire™ manufactured and sold by StriteIndustries Limited of Cambridge, Ontario, Canada), or a profilecomprising two right angle corners and one radiused corner (such as, theSPEED Wire™ manufactured and sold by Strite Industries Limited ofCambridge, Ontario, Canada).

In such cases, a gripping device would be made of a superelasticmaterial or shape memory material, beta-titanium III or another suitablematerial and could be structurally similar to the gripping devices 20and 200 with an arrangement of arm portions and a base portion. Each armportion could include a jaw portion, which together with the other jawportion could form a gripping jaw. The jaw portions could be spacedapart from each other with the gap extending between them sized smallerthan the lateral dimension or width of the arch wire. Moreover, the jawportions could be provided with inner gripping surfaces configured toengage surfaces of the arch wire. In some cases, the profiles of suchinner gripping surfaces could be designed to match closely (orcorrespond to) the shape of the arch wire to be gripped.

Other modifications are possible. In other embodiments, the grippingdevices could be provided with means for facilitating handling of thegripping device to better orient or position the gripping device withina pair of pliers or other tool. In one embodiment, such means could takethe form of grooves, notches or indents registerable with matingprojections on a pair of pliers or other tool. Examples of suchembodiments are shown in FIGS. 18 to 21.

FIGS. 18 and 19 depict a gripping device 300 generally similar togripping device 20 described above in all material respects except thatthe that gripping device 300 includes a pair of opposed, first andsecond, elongate grooves or notches 302 and 304 formed on the grippingdevice body 306. The first groove 302 is defined on the outer surface308 of the first arm portion 310 and runs the entire length of the body306. In this embodiment, the first groove 302 is disposed between thefirst and second corners 312 and 314 of the body 306, closer to secondcorner 314. Similarly, the second groove 304 is defined on the outersurface 316 of the second arm portion 318 and also runs the entirelength of the body 306. The second groove 304 is disposed between thethird and fourth corners 320 and 322 of the body 306, closer to fourthcorner 322. In this embodiment, the grooves 302 and 304 have an arcuateprofile. In other embodiments, the grooves could have a differentprofile and be arranged differently. For instance, in other embodiments,the grooves could be made to extend only partway along the body. Thegrooves could be formed closer to the base portion. Alternatively, theouter surface of each aim portion could be provided with more than onegroove. In still other embodiments, the means for facilitating handlingof the gripping device could take a different form. For example, insteadof providing grooves on the gripping device body which are registerablewith projections on a tool, the gripping device body could be providedwith projections which mate with grooves formed on the work tip surfaceof the tool.

FIGS. 20 and 21 show a gripping device 320 generally similar to grippingdevice 200 described above in all material respects except that thegripping device 320 includes a pair of opposed, first and second,elongate grooves or notches 322 and 324 formed on the gripping devicebody 326. The configuration of the grooves 322 and 324 and theirarrangement on the body 326 is generally similar to the configuration ofgrooves 302 and 304 and their arrangement on body 306 such that nofurther description is required.

FIGS. 22 and 23 show a gripping device 340 in accordance with a sixthembodiment of the present invention. The gripping device 340 isgenerally similar to gripping device 300 described above in all materialrespects except that the gripping device 340 has an arch wire receivingstation 342 that is configured differently than the arch wire receivingstation of gripping device 300 and the gripping device 340 includes adifferent body 343 with a somewhat reinforced (or thicker) base portion344 than the base portion of the gripping device 300.

More specifically, in contrast to the arch wire receiving station of thegripping device 300 which has a circular profile (not unlike arch wirereceiving station 48 shown in FIG. 2A), the arch wire receiving station342 has an oval or elliptical profile (demarcated by dashed lines inFIG. 23). The oval profile is defined substantially by opposed innergripping surfaces 346 and 348 of the first and second jaw portions 350and 352, respectively. In this embodiment, the major axis of the ovalprofile is aligned with the longitudinal centerline CL₁. In otherembodiments, the major axis could be disposed parallel to, but offsetfrom, the longitudinal centerline CL₁.

By virtue of the oval profile of the arch wire receiving station 342,the centre point for the radius of curvature of the inner grippingsurface 346 is offset from the centre point for the radius of curvatureof the inner gripping surface 348, and both centre points are offsetfrom the longitudinal centreline CL₁.

The arch wire receiving station 342 has a short diameter D_(s) (i.e. thediameter measured along its minor axis) defined by the opposing innergripping surfaces 346 and 348. The diameter D_(s) of the arch wirereceiving station 342 is sized slightly smaller than the diameter D₁ ofthe arch wire 50. Preferably, the diameter D_(s) is sized between about10% to about 15% smaller than the diameter D₁. In other embodiments, thesizing of diameter D_(s) may differ.

It has been found that by configuring the arch wire receiving station342 with an oval profile enhanced gripping forces may be generated whenan arch wire of circular or substantially circular cross-section isplaced in the gripping device 340.

In this embodiment, the base portion 344 is more prominent than the baseportion of the gripping device 300 in order to support a pair of firstand second, lateral wing members (or deflectable fingers) 354 and 356which depend from, and are integrally formed with, the base portion 344.The first lateral wing member 354 extends from the corner portion 358 ofthe gripping device body 343 substantially in the direction of the archwire receiving station 342 in a curved, finger-like fashion. The firstlateral wing member 354 terminates at a free end 360 which stops shy ofan elongate groove or notch 362 defined in the gripping device body 343so as not obstruct access thereto. The notch 362 is similar in structureand purpose to notch 302 formed in gripping device body 306. Definedbetween the first lateral wing member 354 and the first arm portion 355of the gripping device body 343 is an elongate gap 364.

Similarly, the lateral wing member 356 extends from the corner portion366 of the gripping device body 343 substantially in the direction ofthe arch wire receiving station 342 in a curved, finger-like fashion.The lateral wing member 356 terminates at a free end 368 which stops shyof an elongate groove or notch 370 defined in the gripping device body343 so as not obstruct access thereto. The notch 370 is similar instructure and purpose to notch 304 formed in gripping device body 306.An elongate gap 372, similar to gap 364, extends between the lateralwing member 356 and the second arm portion 374 of the gripping devicebody 343. As will be explained in greater detail below, the gaps 364 and372 provide a clearance for the lateral wing members 354 and 356 toallow them to move between their respective undeflected positions 380and their respective deflected positions 382.

In other embodiments, the lateral wing members could be configureddifferently.

The purpose of the lateral wing members 354 and 356 is to facilitatehandling of the gripping device 340 by an orthodontist using theorthodontic pliers 110 described earlier (or the like). Morespecifically and as shown in FIGS. 24A and 24B, the lateral wing members354 and 356 serve as resilient stops for preventing the accidentalrelease of the gripping device 340 when it is seated within therectangular rebate 158 formed in the second work tip 140 of the pliers110.

When the lateral wing members 354 and 356 are in their respectiveundeflected positions 380 (shown in FIGS. 23 and 24A), the grippingdevice 340 has a width W₅ (as measured between the outer lateral surface384 of the first lateral wing member 354 and the outer lateral surface386 of the second lateral wing member 356) that is larger than the widthof the rectangular rebate 158. Conversely, when a force is applied onthe gripping device 340 (either manually by the orthodontist usinghis/her finger, or mechanically, using the flange 146 formed on thefirst work of the pliers 110), the lateral wing members 354 and 356 areurged to move to their respective deflected positions 382 (shown inFIGS. 24B), wherein the free ends 360 and 368 encroach onto the gaps 364and 372 such that the width W₅ is slightly smaller than the width of therectangular rebate 158. This allows the gripping device 340 to beaccommodated and captively retained within the rebate 158.

Because the orthodontic gripping device 340 is made from a superelasticmetal alloy, the lateral wing members 354 and 356 are resilient andbiased to their original (undeflected) positions 380. As lateral wingmembers 354 and 356 seek to return to their original positions, theouter lateral surfaces 384 and 386 of the lateral wing members 354 and356 are urged against the walls 388 and 390 which define the rectangularrebate 158, exerting an outward force thereupon. It is these forceswhich operate to retain the gripping device within the rectangularrebate 158.

The attachment of the orthodontic gripping device 340 to an arch wire isgenerally similar to the attachment of the gripping device 20 to archwire 50 described above such that no further description is required.

FIGS. 25 and 26 show a gripping device 400 generally similar to grippingdevice 320 described above in all material respects except that thegripping device 400 includes a different body 402 with a somewhatreinforced (or thicker) base portion 404 from which depend a pair offirst and second lateral wing members 406 and 408. In this regard, thestructure of the base portion 404 and the configuration and arrangementof the lateral wing members 406 and 408 generally resembles those of thebase portion 344 and the lateral wing members 354 and 356 such that thedescription of the latter elements will suffice for the former elements.

It will be appreciated that the gripping devices shown in FIGS. 2A and13A could also be constructed with thickened base portions and lateralwing members as described above.

In the embodiments shown in FIGS. 1 to 5 and 12 to 15, 18 to 23, 25 and26, the gripping devices all have a split-body configurationparticularized by a funnel-shaped entranceway leading into the body andproviding access to the arch wire receiving station. In otherembodiments, the gripping device body could be shaped differently. Inone alternative embodiment, the gripping device body could have anannular or donut shaped body with spaced apart, deflectable arm portions(similar to those described above in the context of the otherembodiments shown in the figures) contained within the envelope of theannular body. In such cases, the entranceway would be defined by theapertures defined in the mesial and distal faces of the body givingaccess to the arch wire receiving station. The gripping device could beplaced onto the arch wire by urging the tip of the arch wire through thearch wire receiving station.

Any of the arch wire gripping devices described above or other arch wiregripping devices constructed in accordance with the principles of thepresent invention could be provided with accessories in the form of ahook (such as hook 172, shown in FIG. 5A), an auxiliary slot, an eyelet,or the like.

Any of the arch wire gripping devices described above or other arch wiregripping devices constructed in accordance with the principles of thepresent invention could be used as end stops (i.e. to restrictdisplacement at the ends of the arch wire). Alternatively, the grippingdevices could be employed to resist displacement of a particularbracket/tooth arrangement relative to the arch wire.

The foregoing disclosure has described exemplary uses of grippingdevices with arch wires. While gripping devices made in accordance withthe principles of the present invention tend to be well-suited for usein conjunction with arch wires, it should be appreciated that use of thegripping device is not limited to arch wires. Gripping devicesconstructed in accordance with the principles of the present inventioncould be employed to similar advantage in conjunction with wires otherthan arch wires or further still, with auxiliary dental devices or otherdental components needing to be gripped or tightly retained. Moreover,the principles of the present invention need not be restricted solely todental/orthodontic applications. With appropriate modifications, thegripping devices described above could be adapted for gripping objectsother than arch wires or dental components.

Although the foregoing description and accompanying drawings relate tospecific preferred embodiments of the present invention as presentlycontemplated by the inventor, it will be understood that variouschanges, modifications and adaptations, may be made without departingfrom the spirit of the invention.

1-20. (canceled)
 21. An orthodontic arch wire stop for attaching to anarch wire, the arch wire stop comprising: a body made of a materialselected from the group consisting of a superelastic metal alloy, coldworked titanium beta III, and solution heat treated and aged titaniumbeta III; the body having an inner surface, a base portion, and firstand second, spaced apart arm portions connected to each other by way ofthe base portion; the first arm portion including a first jaw portionhaving a first inner, archwire-gripping surface; the second arm portionincluding a second jaw portion having a second inner, arch wire-grippingsurface; the first and second inner gripping surfaces being disposedopposite one another in spaced relation, the space between the first andsecond inner gripping surfaces defining a station for receiving the archwire therein, at least a portion of the arch wire receiving stationbeing sized smaller than the arch wire; the base portion including apedestal portion protruding from the inner surface of the body into thearch wire receiving station; the body further including: an entrancewaydefined between the first and second arm portions, the entrancewayproviding access to the arch wire receiving station; and first, second,third and fourth arcuate undercuts formed in the body in communicationwith the arch wire receiving station; the first inner gripping surfaceextending between the first and second undercuts and the second innergripping surface extending between the third and fourth undercuts; thepedestal portion being disposed between the first and third undercuts;the first and second arm portions being resiliently deflectableoutwardly away from each other when the arch wire is admitted throughthe entranceway into the arch wire receiving station; the first andsecond inner gripping surfaces configured to engage the arch wire andapply opposing gripping forces against the arch wire so as to arrestdisplacement of the arch wire stop relative to the arch wire in at leasta mesial or distal direction, when the arch wire is seated within thearch wire receiving station.
 22. The orthodontic arch wire stop of claim21 wherein the pedestal portion is disposed opposite the entranceway.23. The orthodontic arch wire stop of claim 21 wherein the pedestalportion is centrally disposed in the base portion.
 24. The orthodonticarch wire stop of claim 21 wherein the width of the pedestal portion issmaller than the space between the first and second inner grippingsurfaces.
 25. The orthodontic arch wire stop of claim 21 wherein: theentranceway terminates in a throat; and the width of the pedestalportion is smaller than the throat.
 26. The orthodontic arch wire stopof claim 21 wherein the first and third arcuate undercuts are of equalsize.
 27. The orthodontic arch wire stop of claim 21 wherein the secondand fourth arcuate undercuts are of equal size.
 28. The orthodontic archwire stop of claim 21 wherein the body further includes an orthodonticaccessory extending from the base portion; the orthodontic accessorybeing selected from the group consisting of: (a) a hook; (b) anauxiliary slot; and (c) an eyelet.
 29. An orthodontic arch wire stop forattaching to an arch wire having corners, the arch wire stop comprising:a body made of a material selected from the group consisting of asuperelastic metal alloy, cold worked titanium beta El, and solutionheat treated and aged titanium beta III; the body having an innersurface, a base portion, and first and second, spaced apart arm portionsconnected to each other by way of the base portion; the first armportion including a first jaw portion having a first inner, archwire-gripping surface; the second arm portion including a second jawportion having a second inner, arch wire-gripping surface; the first andsecond inner gripping surfaces being disposed opposite one another inspaced relation, the space between the first and second inner grippingsurfaces defining a station for receiving the arch wire therein, atleast a portion of the arch wire receiving station being sized smallerthan the arch wire; the body further including an entranceway definedbetween the first and second arm portions, the entranceway providingaccess to the arch wire receiving station; the base portion including apedestal portion protruding from the inner surface of the body into thearch wire receiving station; the pedestal portion being configured sothat when seated within the arch wire receiving station the arch wire issupported on the pedestal portion with its corners free from engagementwith the base portion; the first and second arm portions beingresiliently deflectable outwardly away from each other when the archwire is admitted through the entranceway into the arch wire receivingstation; the first and second inner gripping surfaces configured toengage the arch wire and apply opposing gripping forces against the archwire so as to arrest displacement of the arch wire stop relative to thearch wire in at least a mesial or distal direction, when the arch wireis seated within the arch wire receiving station.
 30. The orthodonticarch wire stop of claim 29 wherein the body further includes first andsecond arcuate undercuts formed in the body in communication with thearch wire receiving station; the pedestal portion being disposed betweenthe first and second arcuate undercuts.
 31. The orthodontic arch wirestop of claim 30 wherein the first and second arcuate undercuts are ofequal size.
 32. The orthodontic arch wire stop of claim 29 wherein thebody further includes an orthodontic accessory extending from the baseportion; the orthodontic accessory being selected from the groupconsisting of (a) a hook; (b) an auxiliary slot; and (c) an eyelet. 33.An orthodontic arch wire stop for attaching to an arch wire havingcorners, the arch wire stop comprising: a body made of a materialselected from the group consisting of a superelastic metal alloy, coldworked titanium beta III, and solution heat treated and aged titaniumbeta III; the body having a base portion, and first and second, spacedapart arm portions connected to each other by way of the base portion;the first arm portion including a first jaw portion having a firstinner, arch wire-gripping surface; the second arm portion including asecond jaw portion having a second inner arch wire-gripping surface; thefirst and second inner gripping surfaces being disposed opposite oneanother in spaced relation, the space between the first and second innergripping surfaces defining a station for receiving the arch wiretherein, at least a portion of the arch wire receiving station beingsized smaller than the arch wire; the body further including: anentranceway defined between the first and second arm portions, theentranceway providing access to the arch wire receiving station; and aplurality of arcuate undercuts formed in the body in communication withthe arch wire receiving station; each undercut disposed at a locationcorresponding to one corner of the arch wire when the arch wire isseated within the arch wire receiving station so as to provide aclearance between the corner of the arch wire and the body; the firstand second arm portions being resiliently deflectable outwardly awayfrom each other when the arch wire is admitted through the entrancewayinto the arch wire receiving station; the first and second innergripping surfaces configured to engage the arch wire and apply opposinggripping forces against the arch wire so as to arrest displacement ofthe arch wire stop relative to the arch wire in at least a mesial ordistal direction, when the arch wire is seated within the arch wirereceiving station.
 34. The orthodontic arch wire stop of claim 33wherein the first and third arcuate undercuts are of equal size.
 35. Theorthodontic arch wire stop of claim 33 wherein the second and fourtharcuate undercuts are of equal size.
 36. The orthodontic arch wire stopof claim 33 wherein: the body has a longitudinal centerline; the firstand second arm portions are disposed on opposite sides of thelongitudinal centerline; and the first and second arm portions aremirror images of each other.
 37. The orthodontic arch wire stop of claim33 wherein the body has a longitudinal centerline and the body issymmetrical about the longitudinal centerline.
 38. The orthodontic archwire stop of claim 33 wherein the body has a longitudinal centerline andthe body is asymmetrical about the longitudinal centerline.
 39. The archwire stop of claim 33 wherein: the arch wire has a width; and at least aportion of the arch wire receiving station is sized smaller than thewidth of the arch wire.
 40. The orthodontic arch wire stop of claim 39wherein: the arch wire receiving station has a width of constantdimension; and the width of the arch wire receiving station is sizedsmaller than the width of the arch wire.
 41. The orthodontic arch wirestop of claim 39 wherein: the body has a longitudinal centerline; thefirst and second arm portions are disposed on opposite sides of thelongitudinal centerline; the first and second arm portions are mirrorimages of each other; and the first and second inner gripping surfacesare oriented substantially parallel to the longitudinal centerline. 42.The orthodontic arch wire stop of claim 41 wherein: the arch wirereceiving station has a width of variable dimension; and the smallestwidth of the arch wire receiving station is sized smaller than the widthof the arch wire.
 43. The orthodontic arch wire stop of claim 41wherein: the body has a longitudinal centerline; the first and secondarm portions are disposed on opposite sides of the longitudinalcenterline; the first and second arm portions are mirror images of eachother; and the first and second inner gripping surfaces have a skewedorientation relative to the longitudinal centerline, each grippingsurface converging toward each other in the direction of theentranceway.
 44. The orthodontic arch wire stop of claim 33 wherein thebody includes an orthodontic accessory extending from the base portion;the orthodontic accessory being selected from the group consisting of:(a) a hook; (b) an auxiliary slot; and (c) an eyelet.
 45. Theorthodontic arch wire stop of claim 33 wherein the body includes a hookextending therefrom.
 46. The orthodontic arch wire stop of claim 45wherein the hook is carried on one of the first arm portion, the secondarm portion and the base portion.
 47. The orthodontic arch wire stop ofclaim 46 wherein the first arm portion has an outer surface and the hookextends perpendicular to the outer surface of the first arm portion. 48.The orthodontic arch wire stop of claim 46 wherein the first arm portionhas an outer surface and the hook extends from the outer surface of thefirst arm portion on a slant relative to the outer surface.
 49. Theorthodontic arch wire stop of claim 46 wherein the base portion has anouter surface and the hook extends perpendicular to the outer surface ofthe base portion.
 50. The orthodontic arch wire stop of claim 46 whereinthe base portion has an outer surface and the hook extends from theouter surface of the base portion on a slant relative to the outersurface.
 51. An orthodontic arch wire stop for attaching to an archwire, the arch wire stop comprising: a body made of a material selectedfrom the group consisting of a superelastic metal alloy, cold workedtitanium beta III, and solution heat treated and aged titanium beta III,the body having a base portion, and first and second, spaced apart armportions connected to each other byway of the base portion; the firstarm portion including a first jaw portion having a first inner, archwire-gripping surface; the second arm portion including a second jawportion having a second inner, arch wire-gripping surface; the first andsecond inner gripping surfaces being disposed opposite one another inspaced relation, the space between the first and second inner grippingsurfaces defining a station for receiving the arch wire therein, atleast a portion of the arch wire receiving station being sized smallerthan the arch wire; the body further including: an entranceway definedbetween the first and second arm portions, the entranceway providingaccess to the arch wire receiving station; and a plurality of arcuateundercuts formed in the body in communication with the arch wirereceiving station; the plurality of undercuts including first and secondpairs of undercuts, the first pair of undercuts located adjacent thebase portion and the second pair of undercuts located closer to theentranceway than to the base portion; the first and second arm portionsbeing resiliently deflectable outwardly away from each other when thearch wire is admitted through the entranceway into the arch wirereceiving station; the first and second inner gripping surfacesconfigured to engage the arch wire and apply opposing gripping forcesagainst the arch wire so as to arrest displacement of the arch wire stoprelative to the arch wire in at least a mesial or distal direction, whenthe arch wire is seated within the arch wire receiving station.
 52. Theorthodontic arch wire stop of claim 51 wherein the first pair ofundercuts are of equal size.
 53. The orthodontic arch wire stop of claim51 wherein the second pair of undercuts are of equal size.
 54. Theorthodontic arch wire stop of claim 51 wherein the body has alongitudinal centerline and the body is symmetrical about thelongitudinal centerline.
 55. The orthodontic arch wire stop of claim 51wherein the body has a longitudinal centerline and the body isasymmetrical about the longitudinal centerline.
 56. The orthodontic archwire stop of claim 51 wherein: the arch wire has a width; and at least aportion of the arch wire receiving station is sized smaller than thewidth of the arch wire.
 57. The orthodontic arch wire stop of claim 51wherein: the body has a longitudinal centerline; the first and secondarm portions are disposed on opposite sides of the longitudinalcenterline; the first and second arm portions are minor images of eachother; and the first and second inner gripping surfaces are orientedsubstantially parallel to the longitudinal centerline.
 58. Theorthodontic arch wire stop of claim 51 wherein: the body has alongitudinal centerline; the first and second arm portions are disposedon opposite sides of the longitudinal centerline; the first and secondarm portions are mirror images of each other; and the first and secondinner gripping surfaces have a skewed orientation relative to thelongitudinal centerline, each gripping surface converging toward eachother in the direction of the entranceway.
 59. The orthodontic arch wirestop of claim 51 wherein the body includes an orthodontic accessoryextending from the base portion; the orthodontic accessory beingselected from the group consisting of: (a) a hook; (b) an auxiliaryslot; and (c) an eyelet.
 60. The orthodontic arch wire stop of claim 51wherein the hook is carried on one of the first arm portion, the secondarm portion and the base portion.
 61. The orthodontic arch wire stop ofclaim 60 wherein the first arm portion has an outer surface and the hookextends from the outer surface of the first arm portion in one of aperpendicular orientation and a skewed orientation relative to the outersurface of the first arm portion.
 62. The orthodontic arch wire stop ofclaim 60 wherein the base portion has an outer surface and the hookextends from the outer surface of the base portion in one of aperpendicular orientation and a skewed orientation relative to the outersurface of the base portion.
 63. A dental gripping device for attachingto a dental component, the gripping device comprising: a body made of amaterial selected from the group consisting of a superelastic metalalloy, cold worked titanium beta III, and solution heat treated and agedtitanium beta III; the body having a base portion, and first and second,spaced apart arm portions connected to each other by way of the baseportion; the first arm portion including a first jaw portion having afirst inner gripping surface; the second arm portion including a secondjaw portion having a second inner gripping surface; the first and secondinner gripping surfaces being disposed opposite one another in spacedrelation, the space between the first and second inner gripping surfacesdefining a station for receiving the dental component therein, at leasta portion of the receiving station being sized smaller than the dentalcomponent; the body further including: an entranceway defined betweenthe first and second arm portions, the entranceway providing access tothe receiving station; and a plurality of arcuate undercuts formed inthe body in communication with the receiving, station: the plurality ofundercuts including first and second pairs of undercuts, the first pairof undercuts located adjacent the base portion and the second pair ofundercuts located closer to the entranceway than to the base portion;the first and second arm portions being resiliently deflectableoutwardly away from each other when the dental component is admittedthrough the entranceway into the receiving station; the first and secondinner gripping surfaces configured to engage the dental component andapply opposing gripping forces against the dental component, so as toarrest lateral displacement of the gripping device relative to thedental component, when the dental component is seated within thereceiving station.
 64. A gripping device for attaching to an object tobe gripped, the gripping device comprising: a body made of a materialselected from the group consisting of a superelastic metal alloy, coldworked titanium beta III, and solution heat treated and, aged titaniumbeta III; the body having a base portion, and first and second spacedapart arm portions connected to each other by way of the base portion;the first arm portion including a first jaw portion having a first innergripping surface; the second arm portion including a second jaw portionhaving a second inner gripping surface; the first and second innergripping surfaces being disposed opposite one another in spacedrelation, the space between the first and second inner gripping surfacesdefining a station for receiving the object to be gripped therein, atleast a portion of the receiving station being sized smaller than theobject to be gripped; the body further including: an entranceway definedbetween the first and second arm portions, the entranceway providingaccess to the receiving station; and a plurality of arcuate undercutsformed in the body in communication with the receiving station; theplurality of undercuts including first and second pairs of undercuts,the first pair of undercuts located adjacent the base portion and thesecond pair of undercuts located closer to the entranceway than to thebase portion; the first and second arm portions being resilientlydeflectable outwardly away from each other when the object to be grippedis admitted through the entranceway into the receiving station; thefirst and second inner gripping surfaces configured to engage-the objectto be gripped and apply opposing gripping forces against the object tobe gripped so as to arrest lateral displacement of the gripping devicerelative to the object to be gripped, when the object to be gripped isseated within the receiving station.
 65. An orthodontic arch wire stopfor attaching to an arch wire, the arch wire stop comprising: a bodymade of a material selected from the group consisting of a superelasticmetal alloy, cold worked titanium beta III, and solution heat treatedand aged titanium beta III the body having a base portion, and first andsecond, spaced apart arm portions connected to each other by way of thebase portion; the first arm portion including a first jaw portion havinga first inner, arch wire-gripping surface; the second arm portionincluding a second jaw portion having a second inner, arch wire-grippingsurface; the first and second inner gripping surfaces being disposedopposite one another in spaced relation, the space between the first andsecond inner gripping surfaces defining a station for receiving the archwire therein, at least a portion of the arch wire receiving stationbeing sized smaller than the arch wire; the arch wire receiving stationhaving a quatrefoil-like profile; the body further including anentranceway defined between the first and second arm portions, theentranceway providing access to the arch wire receiving station; and thefirst and second arm portions being resiliently deflectable outwardlyaway from each other when the arch wire is admitted through theentranceway into the arch wire receiving station; the first and secondinner gripping surfaces configured to engage the arch wire and applyopposing gripping forces against the arch wire so as to arrestdisplacement of the arch wire stop relative to the arch wire in at leasta mesial or distal direction, when the arch wire is seated within thearch wire receiving station.
 66. The orthodontic arch wire stop of claim65 wherein the body includes an orthodontic accessory extending from thebase portion; the orthodontic accessory being selected from the groupconsisting of; (a) a hook; (b) an auxiliary slot; and (c) an eyelet.